Multilayer pull string bag

ABSTRACT

A web of multilayer material folded and sealed to create a gusseted bag comprising a step cut on the upper end of the bag, the bag further comprising a fold, where the fold enables the upper portion of the bag to be sealed to itself with adhesive, the fold running the width of the bag perpendicular to two side edges of the bag, the bag further comprising a pull string, where the pull string runs laterally from one side edge of the bag to the other, flush against the outer layer of the front panel, below the upper terminating edge of the inner layer of the back panel and above the upper terminating edges of the inner layer of the front panel, the outer layer of the front panel, and the outer layer of the back panel.

BACKGROUND OF THE INVENTION

The invention disclosed herein is generally directed to a multilayeredgusseted bag that may be opened by a consumer for access to the contentsof the bag through the use of a pull string, whereby the pull stringruptures a portion of the bag to create the aforementioned access, aswell as a method for manufacturing such a bag.

Multilayered gusseted bags are well known in the art, as are the use ofa variety of pull string-type opening mechanisms for opening varioustypes of bags. However, functional issues associated with a consumerusing a pull string-type opening mechanism have been seen in the artwhere a step cut open end of an unfinished gusseted bag is folded overthe pull string during manufacture of the bag.

In particular, the art lacks a quality multilayer bag with a pullstring-type opening mechanism that is suitable for holding product of afine particle size, such as flour, particularly during the physicalrigors of transporting the product filled bags, that are cost-effectiveand easily produced.

The present invention aims to address these and other problems in theart.

SUMMARY OF THE INVENTION

The present invention includes a bag comprising a web of multilayermaterial folded and sealed to create a front panel, a back panel, andtwo gussets, wherein the front panel comprises an inner layer and anouter layer, and the back panel comprises an inner layer and an outerlayer, each respective layer possessing an upper terminating edge, thebag further comprising a step cut on the upper end of the bag, the bagfurther comprising a fold, where the fold enables the upper portion ofthe bag to be sealed to itself, the fold running the width of the bagperpendicular to two side edges of the bag, whereby the upperterminating edge of the outer layer of the back panel covers the upperterminating edges of the inner layer of the back panel, the inner layerof the front panel, and the outer layer of the front panel, the bagfurther comprising adhesive, the adhesive residing on the outer layer ofthe front panel in an area bound by the fold, the two opposing sideedges of the front panel, and the upper terminating edge of the outerlayer of the back panel, the bag further comprising a pull string ,where the pull string runs laterally from one side edge of the bag tothe other, extending beyond at least one side edge of the bag, the pullstring residing flush against the outer layer of the front panel, belowthe upper terminating edge of the inner layer of the back panel andabove the upper terminating edges of the inner layer of the front panel,the outer layer of the front panel, and the outer layer of the backpanel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows perspective view of an embodiment of the finishedmultilayered bag of the present invention, with an embodiment of thepull string-type mechanism protruding from the bag. In this particularview, the bag is full and has been sealed at both ends.

FIG. 2 shows the upper end of an embodiment of the finished multilayeredbag of the present invention, this view showing the front panel of thebag, with the pull string-type mechanism protruding from the bag.

FIG. 3 depicts a cross-sectional view of the bag of FIG. 2 along theline 3-3. FIG. 3 shows the spatial relationship between the variouslayers of this particular two layered bag embodiment, particularly withrespect to the pull string.

FIG. 4 depicts a cross-sectional view as in FIG. 4, though the pullstring has been removed from the bag to permit access to the contents ofthe bag, the entry path indicated by the arrow.

FIG. 5 depicts a view of the front of an unfinished bag of the presentinvention, prior to the insertion of the pull string or the adhesive.FIG. 5 aims to show the particular step cut pattern of a preferredembodiment.

FIG. 6, similar to FIG. 5, shows details of the step cut of anunfinished bag embodiment of the present invention, though FIG. 6 showsthe details of the back panel from the inside of the unfinished bag,that is a view without the gussets or front panel.

DETAILED DESCRIPTION OF THE INVENTION

In one aspect, the invention is a multilayered bag with a pullstring-type mechanism that permits access to the inside of an otherwisesealed bag. One of skill in the art would appreciate the distinctionbetween filling a bag with something with a large particle size, such asdog kibble, as opposed to filling a bag with a small particle sizematerial, such as grain flour. Precise craftsmanship of the unfinishedbag, as well as the placement of the pull string-type mechanism andadhesive, is required for a fine particle product. The present inventionaims to provide a suitable solution to the problems associate with pullstring-type mechanisms on multilayered bags that are intended to carrysmall particle size material.

As will be seen in the figures, one aspect of the invention is amultilayered bag. For the purposes of this disclosure, any means used tocreate a multilayered material, such as an adhesive between the layers,does not itself constitute a separate layer. For example two kraft paperlayers adhered to one another through the use of a drip hot melt areonly two layers, the hot melt not constituting a distinct layer.

At its simplest, multilayered means two layers of material adhered toone another prior to or during the manufacture of the bag. The presentdisclosure embraces multilayer configurations with three or more layers.In an embodiment, where two layers are present, both of the layers arekraft paper, the kraft paper layers having been colaminated togetherthrough the use of a hot melt, though any suitable adhesion substrateknown in the art may be used to join the multiple layers. In anotherembodiment, the outer layer is clay coated paper, suitable for acceptingprinting, while the inner layer is kraft paper.

In making the bag, it is preferred that a web of multilayer material isfolded to form the front panel, back panel, and two gussets such thatthe inner layer of the multilayer material faces the inside of the bag,and the outer layer of the multilayer material faces outwardly. The webis formed into a tube that is sealed along the length of the tube andthen folded so as to form the panels and gussets. In an embodiment, anystep cutting required of the bag is performed on the web of multilayermaterial prior to the formation of the bag. As described herein, a stepcut is any cut on the various layers of the bag that is anything otherthan a flush cut.

Throughout the specification, reference is made to a pull string and apull string-type mechanism. This should not be limited to, literally,common string. In any such instance, it should be understood to includeany number of known strands suitable for use in the present invention,including but not limited to fibers, threads, or yarns that are plaitedor twisted together for form a rope, cord, or the like. The pull stringmay additionally be a ribbon or scrim, which includes a woven strip orband of fine material. Additionally, the pull string may be a filament,including a monofilament, of plastic or other suitable material. Thesenon limiting examples are meant for illustrative purposes, and anysuitable length of material that functions to effectively breach theappropriate layers as detailed further herein is considered within thescope of equivalents of a pull string or pull string-type mechanism.

Throughout the specification, reference is made to a step cut. A stepcut, as will be understood by one of ordinary skill in the art, is oneor more cuts made to a bag, whereby the result of the one or more cutsis a bag with, at at least one end, one panel of a greater height thanthe other. In many instances, this includes a progressively lower cut onthe two sides of the folded gusset, where the bag is a gusseted bag,moving from the higher panel to the lower panel. In the context of thepresent disclosure, a step cut refers at least to a back panel that ishigher than the front panel, when the bag is held vertically with theupper end of the bag pointing upward. Examples of step cuts can be seenin the figures, particularly in FIGS. 5 and 6, as will be discussedfurther herein.

Referring now to the figures, FIG. 1 shows an elevated perspective viewof an embodiment of the finished multilayered bag 100 of the presentinvention, with an embodiment of the pull string-type mechanism 102protruding from the bag. In this particular view, the bag is full andhas been sealed at both ends.

FIG. 2 shows the upper end 142 of an embodiment of the finishedmultilayered bag 100 of the present invention, this view showing thefront panel 104 of the bag, with the pull string 102 protruding from thebag. In this view, a portion of the back panel 110 that has been foldedat a fold 124 over the front panel 104 is visible.

In an embodiment, a partial destruction of the outer layer of the backpanel 106 is present in the form of a linear series of perforations 108on the front of the bag and generally in parallel alignment with thepull string 102 so as to permit easier access to the interior of the bagby a consumer. These perforations 108, when present, will run parallelto the pull string on one or both sides of the bag 100 in a length aboutequal to the length of the folded gusset from the side of the bagtowards the inner cavity of the bag. The reason for this particulardistance is to compensate for the extra amount of multilayered materialthat must be breached by the pull string to open the bag due to thelocation of the fold 124 and the presence of the gussets, as can beappreciated in the other figures, most notably FIGS. 5 and 6.

FIG. 3 depicts a cross-sectional view of the bag of FIG. 2 along theline 3-3. FIG. 3 shows the spatial relationship between the variouslayers of this particular two layered bag embodiment, particularly withrespect to the pull string 102. In this embodiment, the front panel iscomprised of an outer layer 116 and an inner layer 118, these layershaving been at least partially colaminated together. Similarly, the backpanel is comprised of an outer layer 122 and an inner layer 120 thathave been similarly at least partially colaminated. These two panels andfour layers have all been folded at a fold 124. The pull string 102 hasbeen placed on the bag such that both the outer layer 116 and the innerlayer 118 of the front panel cover the pull string 102 when the bag hasbeen folded at the fold 124. However, after folding the bag at the fold124, the upper terminating edge 138 of the inner layer 120 of the backpanel terminates before the pull string 102, while the outer layer 122of the back panel covers the top edges of each of the remaining layers.A layer of adhesive 112 has been placed on below the fold 124, past thepull string 102 down to the termination of the outer layer 122 of theback panel.

In a preferred embodiment, the pull string 102 is flush against theouter layer 116 of he front panel and is essentially surrounded byadhesive 112. In stating that the pull string be flush against the frontpanel, it is understood that adhesive may permeate in and around thepull string in an unpredictable manner and, by virtue of the volume ofadhesive that might be used, portions of the pull string may notactually make direct contact with the front panel, though the pullstring runs the length of the bag from side edge to side edge. Anyembodiment where pull string and adhesive overlap and run in essentiallythe same linear distance from one side edge of the bag to the other sideedge is considered within the scope of equivalents of the inventiondisclosed herein

FIG. 4 depicts a cross-sectional view as in FIG. 3, though the pullstring has been removed from the bag 100 of FIG. 3 to permit access tothe contents of the bag, the entry path indicated by the arrow 114. Dueto the at least partial colamination of the respective layers of thefront and back panels, and due to the presence of the adhesive layer,the portion of the back panel 110 above the location of the pull stringmay be unfolded along the fold 124. Although FIGS. 3 and 4 show anembodiment the bag of the present invention that is a two layered bag,additional layers may be used.

FIG. 5 depicts a view of the front of the upper end 142 of an unfinishedbag of the present invention, prior to the insertion of the pull stringor the adhesive. FIG. 5 aims to show the particular step cut pattern ofa preferred embodiment. The front panel 104, of which the outer layer116 is visible in this figure, has been cut to permit the gusset 106 tobe adhered to the front panel with adhesive after the bag is folded overthe fold 124. Additionally, the back panel 110, of which the inner layer122 is visible in this figure, will be similarly adhered to the frontpanel 104 with adhesive, as can be seen further in FIG. 3.

FIG. 6, similar to FIG. 5, shows details of the step cut of anunfinished bag 100 embodiment of the present invention, though FIG. 6shows the details of the back panel 110 from the inside of theunfinished bag, that is a view without the gussets or front panel. Inthis figure, both the outer layer 122 and inner layer 120 are visible.This figure illustrates the ideal placement of the pull string 102,which is determined by the distance 132 between the fold 124 and theupper terminating edge 138 of the inner layer of the back panel 120between the gussets. The string may be placed at a location 126 that isthat very nearly, but slightly greater than, the same distance 132 belowthe fold 124. In such an instance, in an embodiment, the pull stringabuts and is substantially parallel to the upper terminating edge of theinner layer of the back panel.

In the preferred embodiment depicted in FIGS. 3 and 4, when the bag hasbeen folded at the fold 124, both the upper terminating edge 134 of theouter layer of the front panel and the upper terminating edge 136 of theinner layer of the front panel pass over the pull string 102, whereasthe upper terminating edge 138 of the inner layer of the back panelterminates prior to the location of the pull string. In this embodiment,the upper terminating edge 140 of the outer layer of the back panelpasses over the upper terminating edges 134, 136, 138 of every otherlayer, as well as the pull string.

FIG. 6 additionally illustrates the ideal placement of the adhesive,which is applied at a substantially uniform height in a generallyrectangular area across the bag, between the side edges of the bag 144.The distance 128 between the upper terminating edge 140 of the outerlayer 122 of the back panel 110 to the fold 124 is the same distance 130below the fold 124 that adhesive is applied across the outer layer 116of the front panel 104, between the side edges of the bag 144.

In operation, a user would grasp one end of the pull string 102 and pullit from one side of the bag to the other, moving laterally across theupper end 142 of the bag 100, thereby breaching multiple layers of thematerial that comprise the bag, between the side edges of the bag 144.In so doing, access 114 to the inside of the bag and its contents isachieved.

Reviewing FIGS. 3 through 6 together, one can appreciate the value ofthe unique step cut of this invention. The cuts of the front panel 104and the gussets 106 together prevent any of the inner layer 120 of theback panel 110 from receiving any of the adhesive 112 when the bag isfolded. In this way, the removal of the pull string 102 perforates theouter layer 122 of the back panel 110 so that the portion of the outerlayer 122 that has not received an adhesive bond to the front panel 104,as well as the inner later 120 of the back panel 110 may both be freelyunfolded at the fold 124 to permit access to the contents of the bag 100through the thus-created bag access 114. As such, the location of thepull string 126 relative to the inner layer 118 of the back panel 110when folded is critical. It is preferable that the pull string 102receive at least some of the adhesive 112 to prevent lateral movement ofthe string, while it is necessary at the same time the manufacturerprevents the inner layer 118 of the back panel 110 from receiving anyadhesive 112.

The inventors discovered through testing that the location of the pullstring 102 relative to the upper terminating edge 138 of the inner layerof the back panel, as seen throughout the figures, particularly in FIG.6, is critical to the performance of the bag of the present invention,particularly in holding product of a fine particle size, such as flour,particularly during the physical rigors of transporting the productfilled bags. Bags of the present invention, when filled with aroundthirty pounds of flour, were subjected to a series of tests to replicatethe physical effects of a typical shipping regimen, and the bags passedthe incline-impact shock test, a machine compression test, and avibration test.

Where the pull string 120 was located at or above the upper terminatingedge 138 of the inner layer of the back panel, in a parallel alignmentthat was closer to the fold 124 than the ideal placement indicated inFIG. 6 as reference character 126, the bags failed to open as desiredand an imperfect access path 114, if any, was created.

While it is preferred that the pull string location 126 be just belowthe upper terminating edge 138 of the inner layer of the back panel, thepull string 120 may be placed on the bag in the area between the upperterminating edges 134, 136 of the layers of the front panel 104. In suchan embodiment, the lack of adhesive or hot melt adhering the outer layerof the back panel 122 to the front panel 104 and the absence of theinner layer of the back panel 120 due to its termination 138 location,will still permit the creation of the access path 114 through theremoval of the pull string 102 by a user, as seen in FIG. 4.

Therefore, in a particularly preferred embodiment, the present inventionincludes a bag 100 comprising a web of multilayer material folded andsealed to create a front panel 104, a back panel 110, and two gussets106, wherein the front panel comprises an inner layer 118 and an outerlayer 116, and the back panel comprises an inner layer 120 and an outerlayer 122, each respective layer possessing an upper terminating edge,the bag further comprising a step cut on the upper end 142 of the bag,the bag further comprising a fold 124, where the fold enables the upperend of the bag to be sealed to itself, the fold running the width of thebag perpendicular to two side edges of the bag 144, whereby the upperterminating edge 140 of the outer layer of the back panel covers theupper terminating edges 134, 136, 138 of the inner layer of the backpanel, the inner layer of the front panel, and the outer layer of thefront panel, the bag further comprising adhesive 112, the adhesiveresiding on the outer layer of the front panel in an area 130 bound bythe fold, the two opposing side edges of the front panel, and the upperterminating edge of the outer layer of the back panel, the bag furthercomprising a pull string 102, where the pull string runs laterally fromone side edge 144 of the bag to the other, extending beyond at least oneside edge of the bag, the pull string residing flush against the outerlayer 116 of the front panel, below the upper terminating edge 138 ofthe inner layer of the back panel and above the upper terminating edges134, 136, 140 of the inner layer of the front panel, the outer layer ofthe front panel, and the outer layer of the back panel.

The multilayer material, in a preferred embodiment, is a pair ofcolaminated kraft paper layers. In another preferred embodiment, theouter layers of the front panel and the back panel are the same andselected from a group consisting of clay coated paper and kraft paper,where the inner layers of the front panel and the back panel are kraftpaper.

In an embodiment, the bag further comprises a linear series ofperforations 108 on the outer layer 122 of the back panel, theperforations located on front of the bag and generally in parallelalignment with the pull string 102, and running parallel to the pullstring one side of the bag in a length about equal to the length of thefolded gusset from the side of the bag towards the inner cavity of thebag. In another embodiment, when present, the linear series ofperforations are located on both sides of the bag.

It should be understood that the aforementioned embodiments are forexemplary purposes only and are merely illustrative of the many possiblespecific embodiments that can represent applications of the principlesof the invention. Without departing from the spirit and scope of thisinvention, one of ordinary skill in the art can make various changes andmodifications to the invention to adapt it to various usages andconditions, including those not specifically laid out herein. As such,those changes and modifications are properly, equitably, and intended tobe, within the full range and scope of equivalents of the inventiondisclosed, described and claimed herein.

I claim:
 1. A bag comprising a web of multilayer material folded andsealed to create a front panel, a back panel, and two gussets, whereinthe front panel comprises an inner layer and an outer layer, and theback panel comprises an inner layer and an outer layer, each respectivelayer possessing an upper terminating edge at an upper end of the bag,the bag further comprising a step cut on the upper end of the bag, thebag further comprising a fold, where the fold enables the upper end ofthe bag to be sealed to itself, the fold running the width of the bagperpendicular to two side edges of the bag, whereby the upperterminating edge of the outer layer of the back panel covers the upperterminating edges of the inner layer of the back panel, the inner layerof the front panel, and the outer layer of the front panel, the bagfurther comprising adhesive, the adhesive residing in a generallyrectangular area on the outer layer of the front panel in an area boundby the fold, the two opposing side edges of the front panel, and theupper terminating edge of the outer layer of the back panel, the bagfurther comprising a pull string, where the pull string runs laterallyfrom one side edge of the bag to the other side edge, extending beyondat least one side edge of the bag, the pull string residing flushagainst the outer layer of the front panel, below the upper terminatingedge of the inner layer of the back panel and above the upperterminating edges of the inner layer of the front panel, the outer layerof the front panel, and the outer layer of the back panel.
 2. The bag ofclaim 1, where multilayer material is a pair of colaminated kraft paperlayers.
 3. The bag of claim 1, where the outer layers of the front paneland the back panel are the same and selected from a group consisting ofclay coated paper and kraft paper, where the inner layers of the frontpanel and the back panel are haft paper.
 4. The bag of claim 1 furthercomprising a linear series of perforations on the outer layer of theback panel, the perforations located on front of the bag and generallyin parallel alignment with the pull string, and running parallel to thepull string one side of the bag in a length about equal to the length ofthe folded gusset from the side of the bag towards the inner cavity ofthe bag.
 5. The bag of claim 4 where the linear series of perforationsare located on both sides of the bag.
 6. The bag of claim 1, wherein thepull string abuts and is substantially parallel to the upper terminatingedge of the inner layer of the back panel.